Clutch gear change grating

[MikeCrook]

I have changed the plates and springs as well as the plunger screw on my 1936 ng 350.

The gear change is smooth to start with but grinds crashes after a while especialy when changing down to 2nd and 1st. I've tried readjusting the clutch as per the manual still no improvement.

Any advise please

Thanks

[paul.jameson]

What lubricant have you in the gearbox?

[MikeCrook]

The recomended one sold by drags, I've checked the level.

The problem is intermittant only occuring when bike is being ridden, not present when stationary at start or end of ride ?

Thanks Paul

[will_curry]

After a longish run the gearchange on my vintage Ariel can get quite noisy.
This is usually down to one or more of the clutch spring screws slackening
and causing the pressure plate not to lift squarely and the clutch drag a
little. When cold there is enough drag in the gearbox to free things but as
it warms up rhis doesn't happen and things get noisy. The box is a
3-plate Burman QDH.

[MikeCrook]

Thanks Will, I have a 2 plate clutch, I will remove cover and check it squarely on lifting.
I also put a new plunger rod and screw adjuster. I put the ball bearing back even though drags said it was not necessary ?


Thanks for your advice and any further suggestions .

[will_curry]

I've assumed that the ball was there to accommodate those circumstances when
the bits at either end of the pushrod were turning at different rates, basically when
the clutch is being slipped. Once the clutch is fully disengaged the mainshaft should
stop turning and both ends of the pushrod are static.

I know that the ball is inside the pressure plate on the Vintage Ariel and I can't help
but wonder if that's contributing in part to the difficulty in getting the pressure plate
to lift squarely and to the frequency with which it needs resetting. Perhaps I'd be better
off with the flat end of the pushrod in the pressure plate and the ball somewhere
nearer the operating arm.

[MikeCrook]

Good idea, makes sense Thanks Will I'll try setting up the clutch without the ball in the pressure plate.

[MikeCrook]

I have removed the ball bearing at the pressure plate, reset the throw of the opperating lever and the plunger screw , a number of times but still the gear change from 3rd to 2nd and 2nd to 1st are clunkey with occasional grating . Only happens when bike is ridden not stationary

Do I need to slacken off the pressure plate springs ? I have them set as per manual and checked for square release when clutch opperated both stationary and engine running .
The gap from the plain end plate to the pressure is about 1/4 inch .

Help please

[will_curry]

Two thoughts occur:

One is that there is a degree of technique involved - a Burman gearbox does not make
quick changes.

The other is that an overly tight primary chain can cause gearchange issues.

[MikeCrook]

Thanks Will,
I did tighten the primary chain ,perhaps too much !
Not something I'd have considered.

Thanks again for all your help.